React Mongoose Error - URI parameter must be string but returns 'Undefined' from .env file

Question

The error message after i run 'npm run backend'.

Code in .env file -

PORT=5000
MONGO_URI='mongodb://127.0.0.1:27017/test'

**code in index.js file - **

// packages
import path from "path";
import express from "express";
import dotenv from "dotenv";
import cookieParser from "cookie-parser";

// Utiles
import connectDB from "./config/db.js";


dotenv.config();
const port = process.env.PORT || 5000;

connectDB();

const app = express();

app.use(express.json());
app.use(express.urlencoded({ extended: true }));
app.use(cookieParser());

app.get("/api/config/paypal", (req, res) => {
  res.send({ clientId: process.env.PAYPAL_CLIENT_ID });
});


app.listen(port, () => console.log(`Server running on port: ${port}`));

**code in db.js file - **

import mongoose from "mongoose";

const connectDB = async () => {
  try {
    console.log(process.env.MONGO_URI); // Add this line
    await mongoose.connect(process.env.MONGO_URI);
    console.log(`Successfully connected to MongoDB `);
  } catch (error) {
    console.error(`ERROR: ${error.message}`);
    process.exit(1);
  }
};

export default connectDB;

.env and db.js is in the folder config, index.js is in the folder utils

Learning react and javascript currently. I learn by watching tutorials online then creating my own projects.

Im trying to output 'Successfully connected to MongoDB ' in the db file but i get the URI error.

i tried printing process.env.MONGO_URI via console log and it prints undefined. I really need help and explanation why its not working

Answer 1

To make life easier for yourself, follow the deafult documentation and move your .env file into your root directory then update as follows:

import path from "path";
import express from "express";
import "dotenv/config"; //< Change to this
import cookieParser from "cookie-parser";

// Utiles
import connectDB from "./config/db.js";

const port = process.env.PORT || 5000;

await connectDB(); //< top level await 
//...